Bodyweight plays no role in pleasure of eating, says study

The pleasure of eating, and the desire to stop, is not affected by bodyweight, says a new study that could help in the search for a solution to the obesity epidemic.

Some studies have reported a defect on the normal mechanism that controls the pleasure linked to the aroma and taste of food may explain overeating. This has seen the food industry come under increasing pressure to accept some or all responsibility for the growing obesity epidemic, and help with a solution to the problem by producing foods with lower calorific value but the same flavour and aroma.

"It is of great interest to detect whether there is a difference in sensory-specific satiety between lean and obese subjects," explained lead author Laurent Brondel. "Actually, reduce sensory-specific satiety could be a factor through which taste could promote excessive energy intake and contribute to the development or maintenance of obesity in humans."

The new research, by researchers from the Centre Europeen des Sciences du Gout (UMR CNRS 5170) in Dijon, along with Austrian collaborators from AKH, Wahringer Gurtel and Vienna University, reports that hedonic pleasures may be no different between lean and overweight/obese people, a result that deepens our understanding of the eating habits and the relative pleasures of both overweight/obese and lean subjects.

"Sensory-specific satiety for simple foods has a similar effect in a large stable weight population differing in its corpulence, with no influence of gender and age," said Brondel. "This conclusion is important because the debate concerning possible differences between lean and overweight subjects with regard to sensory-specific satiety remains controversial."

Sensory-specific satiety is one of the negative feedback mechanisms that humans have to stop them eating. It is defined as a decrease in pleasure created by consuming food that is just eaten, which leads to a decreased desire to eat more food.

The research, published in the International Journal of Obesity, focussed on a group of 144 subjects (50 per cent women, age range 17 to 62), with a range of body mass indices from 17 to 39 kg per sq. m.

The researcher investigated the effects of food ingestion on the olfactory pleasure (OP) and flavour pleasure (FP) of the subjects. The volunteers were offered six foods from three classes: cucumber and tomato, pineapple and banana, and peanut and pistachio. The subjects were then assigned to one of the groups according to the subjects' preference. They were then asked to evaluate the six foods (OP), allowed to eat as much of the preferred food as they wished (FP), and then asked to evaluate all six food again (OP).

Dr. Brondel and his co-workers report that sensory-specific satiety was found to be the same in the overweight/obese volunteers as in the normal weight ones. No association between BMI and co-called hedonic parameters (OP and FP) or intakes (quantity and volume) was observed.

"Interestingly, the sensory-specific satiety we observed was not related to the subjects BMI but rather correlated with the ingested amounts," said Brondel.

"This suggests that overweight and lean subjects have similar hedonic control of food intake with simple foods."

The researchers also said that the study underlines the importance of stimulation of sensors in the gastrointestinal tract to tell the brain when sufficient food has been eaten and how this may interact with sensory-specific satiety to stop eating.

Over 300m adults are obese worldwide, according to latest statistics from the WHO and the International Obesity Task Force. About one-quarter of the US adult population is said to be obese, with rates in Western Europe on the rise although not yet at similar levels.